1. Field of the Invention
The present invention relates to a midsole or insole or shoe sole for footwear, and more particularly to a shoe sole having a soft cushioning device for providing a shock absorbing effect and for comfortably contacting or engaging with the feet of the users.
2. Description of the Prior Art
Various kinds of typical sports shoes have been developed and provided for jogging, running or other sport purposes, and comprise two basic requirements. The principal task of the shoe is to help or to facilitate running or walking, and to allow runners to move easily. The other task of the shoe is to protect the feet from running exertion, so that runners' optimum performance may be preserved or maintained in races. In addition, in a consumer's point of view, longer life of a shoe sole is preferred. To achieve the aforementioned functions, many different shoe soles have been developed.
Suitable or required resilience of shoe soles can be obtained in many different ways. For example, a traditional shoe sole is made of foamable materials for providing a suitable elasticity, and a rubber layer is combined with the foamable material for protecting the foamable material. However, the resilience or the cushioning effect of the foamable materials and the rubber layer is not good enough, and the feet of the users may not be comfortably contacted or supported with the foamable materials and/or the rubber layer of the shoe sole.
Another traditional shoe sole includes an air cushion structure. However, the cost of air cushioned shoe sole is high and the procedure of manufacturing is complicated. In addition, sometimes, unnecessary deformations may take place in the shoe soles of air cushion structure. Accordingly, a shoe sole with sufficient and proper elasticity as well as long life and comparatively low cost of manufacture is needed.
U.S. Pat. No. 4,364,186 to Fukuoka, U.S. Pat. No. 4,468,869 to Fukuoka, and U.S. Pat. No. 4,831,749 to Tsai disclose three of the typical ventilated footwears, each including a series of openings formed therein, for air cushioning purposes. However, the openings are deeply formed within the shoe portion by such as molding or mold injection processes, and thus the feet of the users also may not be comfortably contacted or supported with the foamable materials and/or the rubber layer of the shoe sole.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional shoe soles.